1. Field of the Invention
The present invention relates to an optical apparatus that can execute a manual focus mode that enables a focus lens to move in an optical axis direction so as to provide focusing through manual operating.
2. Description of the Related Art
In a manual focus (which may be referred to as “MF” hereinafter), a focus lens is moved beyond a position to be focused and this position is set to an in-focus position. Since the manual focus is demanded to quickly obtain the in-focus position with a small amount of manual operations, it is important to set a unit moving amount that is a moving amount of the in-focus position per unit operation of the manual operating unit. An excessively small unit moving amount will improve the in-focus accuracy but require a large amount of manual operations and lowers the operability. An excessively large unit moving amount will reduce an amount of manual operation but lower the focusing accuracy because the focus lens cannot be positioned at a desired position.
Conventionally, Japanese Patent Laid-Open No. (“JP”) 2005-142660 discloses a method for setting this unit moving amount (or corresponding driving amount of the focus lens) in accordance with the object distance, and JP 2011-49661 discloses two types of unit moving amounts, such as a micro driving amount and a rough driving amount. However, JP 2011-49661 does not disclose a concrete driving amount.
JPs 2005-142660 and 2011-49661 do not thoroughly examine a unit moving amount (or corresponding driving amount of the focus lens) of the in-focus position in the manual focus, and it is difficult to handle both the operability and the focusing accuracy.